Brief Summary

Brief Summary

Loriciferans are microscopic animals living between the particles of marine sediments. Discovered in 1983 off the coast of France by the Danish zoologist R. M. Kristensen, about 100 species have so far been collected, though (as of 2010) only a third of those have been described. Researchers continue to find new species, indicating that this is an abundant and cosmopolitan taxon, with worldwide distribution and occurring in sediments from shallow to deep water. Loricifera are interesting as “masters of miniturization” (Rundell & Leander 2010) but also as “the first evidence of a metazoan life cycle that is spent entirely in permanently anoxic sediments” (Danovaro et al 2010).

Loriciferans are similar in size to large single-celled protozoans (< 0.5 mm) but are multicellular, with about 10,000 specialized cells creating a tiny but complex body with a brain, digestive and excretory systems, specialized appendages, sense organs, musculature and locomotory functions, separate sexes, and a protective external cuticle (the “lorica”) into which the “introvert” containing the mouth cone and head can be retracted (Ruppert et al 2004).